Flat plate stacked-type fuel reforming apparatus

Abstract

A fuel reforming apparatus comprising a liquid feed heating portion, an evaporation portion, a steam superheating portion, a reforming portion, a shift reaction portion, a CO oxidization portion, a catalytic combustion portion, and a heat recovery portion. These portions are constituted by flat plates provided with heat-transfer fins in the interior and are stacked into an integral structure, thereby obtaining a temperature distribution along a stacked direction so that the flat plate elements reach a temperature suitable for reforming, combustion, evaporation, shift, and CO oxidization.

What is claimed is: 
     
       1. A fuel reforming apparatus comprising portions which include: a liquid feed heating portion for heating liquid feed which comprises water and alcohol or hydrocarbon;   an evaporation portion for evaporating the heated liquid feed to generate feed gases;   a steam superheating portion for superheating the feed gases from an evaporation temperature to a reforming temperature;   a reforming portion for generating hydrogen-rich reformed gases from the superheated feed gases by reforming catalysts;   a catalytic combustion portion for supplying reforming heat to said reforming portion and evaporation heat to said evaporation portion and said steam superheating portion from heat generated by catalytic combustion;   a CO oxidization portion for reducing CO contained in the reformed gases that pass through and emerge from said catalytic combustion portion by catalytic oxidization; and   a heat recovery portion for using exhaust heat from high-temperature combination gases obtained by catalytic combustion as heat sources for said steam superheating portion and said evaporation portion; and   wherein each of said portions are formed of flat plate elements made of a light alloy, the flat plate elements having a manifold for performing intake and exhaust with respect to their periphery and heat-transfer fins in the interior thereof, and said flat plate elements being stacked into an integral construction such that said catalytic combustion portion, reforming portion, steam superheating portion, heat recovery portion, evaporation portion, CO oxidization portion, and liquid feed heating portion are in close proximity to one another from the catalytic combustion portion at a high-temperature side to the liquid feed heating portion at a low-temperature side.   
     
     
       2. The fuel reforming apparatus as set forth in claim 1, wherein said catalytic combustion portion is divided into a plurality of portions and inserted between the reforming portion and the steam superheating portion and wherein a fuel portion of said catalytic combustion portion and the reforming portion are stacked in contact with each other. 
     
     
       3. The fuel reforming apparatus as set forth in claim 1, wherein said heat recovery portion is divided into a plurality of portions and inserted between the evaporation portion and the CO oxidization portion and wherein said heat recovery portion and said evaporation portion are stacked in contact with each other. 
     
     
       4. The fuel reforming apparatus as set forth in claim 1, wherein, when stacking the flat plate elements of said catalytic combustion portion, reforming portion, steam superheating portion, heat recovery portion, evaporation portion, CO oxidation portion and liquid feed heating portion to define a main stacked body, a pair of said reforming portions or a pair of catalytic combustion portions is provided in the center of said main stacked body, wherein said main stacked body comprises first and second identical stacked bodies that are symmetrically stacked about a symmetrical plane. 
     
     
       5. The fuel reforming apparatus as set forth in claim 1, wherein: said CO oxidization portion and reforming portion each further comprises a flat plate element having heat-transfer fins fixed to the interior, each heat-transfer fin of the CO oxidization portion flat plate element and the reforming portion plate element being filled on the inner side with a CO oxidization catalyst or a reforming catalyst, respectively;   said heat recovery portion and steam superheating portion each further comprises a flat plate element having a combustion gas passage and a steam passage formed with heat-transfer fins alone; and   said flat plate elements are stacked by providing at least one fluid turn-back passage in a stacked direction of said flat plate elements so that fluid turns back at an end of said flat plate element, when said fluid passes the inner side of each heat-transfer fin.   
     
     
       6. The fuel reforming apparatus as set forth in claim 5, wherein said CO oxidization portion comprises flat plate elements provided with one or more turn-back passages, the evaporation portion is provided in contact with the flat plate element of an inlet of said CO oxidization portion into which the reformed gases flow, the liquid feed heating portion is provided in contact with the flat plate element of an outlet of said CO oxidization portion from which the reformed gases flow out, a heat conductor is provided on a boundary surface where the flows of said reformed gases and said liquid feed and steam become opposite flows, and a heat insulator is provided on a boundary surface where the flows of said reformed gases and said liquid feed and steam become parallel flows, thereby obtaining temperature distribution which is high in temperature at the inlet portion and low in temperature at the outlet portion in the stacked direction of said CO oxidization portion and in the directions of said reformed gases and said liquid feed and steam. 
     
     
       7. The fuel reforming apparatus as set forth in claim 5, wherein said CO oxidization portion dispersedly supplies CO oxidization air in correspondence with the CO concentration distribution along a direction of flow in said CO oxidization portion, by alternately stacking a plurality of turn-back passages of reformed-gas chambers and CO oxidization air chambers so that the flows of the reformed gases and the CO oxidization air become parallel flows and also by providing a CO oxidization air dispersion plate with a plurality of dispersion holes between flat plate elements of the reformed-gas chambers and the CO oxidization air chambers so that the air amount distribution in the stacked direction is controlled by the configuration of the dispersion hole and the passage resistance of a fluid passage leading to the dispersion hole. 
     
     
       8. The fuel reforming apparatus as set forth in claim 1, wherein a surface-division heat recovery portion, formed by dividing a surface of the heat recovery portion into an evaporation catalytic combustion portion and a combustion gas heat recovery portion, is provided in close proximity to an upper or lower portion of the evaporation portion and wherein said evaporation catalytic combustion portion and said combustion gas heat recovery portion are alternately disposed on the surface along a flow of steam on the evaporation surface of said evaporation portion. 
     
     
       9. The fuel reforming apparatus as set forth in claim 8, wherein an evaporation temperature corresponding to liquid feed is set by varying the ratio of the areas of the evaporation catalytic combustion portion and the combustion gas heat recovery portion in said surface-division heat recovery portion. 
     
     
       10. The fuel reforming apparatus as set forth in claim 8, wherein: the evaporation portion is formed by two stages, a liquid feed evaporation portion and a water evaporation portion;   a surface-division heat recovery portion is formed by dividing a surface of the heat recovery portion into an evaporation catalytic combustion portion and a combustion gas heat recovery portion;   said liquid feed evaporation portion and said water evaporation portion are provided in close proximity to said surface-division heat recovery portion, respectively; and   CO oxidization portions are stacked between said liquid feed evaporation portion and said water evaporation portion and outside said liquid feed evaporation portion and said water evaporation portion, respectively.   
     
     
       11. The fuel reforming apparatus as set forth in claim 10, wherein an area ratio of the evaporation catalytic combustion portion to said combustion gas heat recovery portion is reduced at a portion adjacent to the liquid feed evaporation portion where the evaporation temperature is low, and is increased at a portion adjacent to the water evaporation portion where the evaporation temperature is high. 
     
     
       12. A fuel reforming apparatus comprising portions which include: a liquid feed heating portion for heating liquid feed which comprises water and alcohol or hydrocarbon;   an evaporation portion for evaporating the heated liquid feed to generate feed gases;   a steam superheating portion for superheating the feed gases from an evaporation temperature to a reforming temperature;   a reforming portion for generating hydrogen-rich reformed gases from the superheated feed gases by reforming catalysts;   a catalytic combustion portion for supplying reforming heat to said reforming portion and evaporation heat to said evaporation portion and said steam superheating portion from heat generated by catalytic combustion;   a shift reaction portion for reducing carbon monoxide (CO) contained in the reformed gases generated by said reforming portion;   a CO oxidization portion for reducing the CO contained in the reformed gases emerging from said shift reaction portion by catalytic oxidization; and   a heat recovery portion for using exhaust heat from high-temperature combustion gases obtained by catalytic combustion as heat sources for said steam superheating portion and said evaporation portion; and   wherein each of said portions are formed of flat plate elements made of a light alloy, the flat plate elements having a manifold for performing intake and exhaust with respect to their periphery and heat-transfer fins in the interior thereof, and said flat plate elements being stacked into an integral construction such that said catalytic combustion portion, reforming portion, steam superheating portion, heat recovery portion, shift reaction portion, evaporation portion, CO oxidization portion, and liquid feed heating portion are in close proximity to one another from a high-temperature side to a low-temperature side.   
     
     
       13. The fuel reforming apparatus as set forth in claim 12, wherein said catalytic combustion portion is divided into a plurality of portions and inserted between the shift reaction portion and the evaporation portion and wherein a fuel portion of said catalytic combustion portion and the evaporation portion are stacked in contact with each other. 
     
     
       14. The fuel reforming apparatus as set forth in claim 12, wherein said heat recovery portion is divided into a plurality of portions and inserted between the evaporation portion and said heat recovery portion and wherein said shift reaction portion and said evaporation portion are stacked in contact with each other.